Whatever charms turned the musical “Jersey Boys” into a Tony-winning Broadway hit are sorely missed in Clint Eastwood’s tone-deaf corpse of a movie. Late to the game, blandly cast and scripted with every Italian-American cliche, it is Eastwood’s worst film as a director.

And it does Franki Valli and the Four Seasons no great favors either, overselling their cultural significance, rendering their story in broad, tried and trite strikes.

“Jersey Boys” follows little Frankie Castelluccio (John Lloyd Young), son of a New Jersey barber, from his teens, training to follow in dad’s footsteps. But all the Italian Americans in Belleville see bigger things for Frankie — whose voice could make him “bigger than Sinatra.”

If only he can get a break. If only he can stay out of trouble with his musician pal, Tommy DeVito (Vincent Piazza), a “two-bit hustler” who does break-ins and “it fell off a truck” thefts in between gigs.

Frankie is the gang’s lookout, signaling that the cops are coming by screeching “Silhouettes,” the doo-wop hit by The Rays.

Since this happens in 1951 and the song didn’t come out until 1957, that Frankie was plainly ahead of his time. Or Eastwood has turned careless with the details.

'Jersey Boys'

The story arc — struggles to get a record deal, inspiration in the studio, breaking out on radio, then money troubles, internal strife, tragedy, etc. — is so over-familiar that it lacks a single surprise.

Recycling that corny “DJ locks himself in the studio playing their first hit over and over again until the cops break down the door”? “The Buddy Holly Story” did it better back when Gary Busey was thin.

Members of the group turn, mid-scene (mid-concert, sometimes) to the camera and narrate their story — Tommy, Frankie, Nick Massi (Michael Lomenda) and Bob Gaudio (Erich Bergen). Characters talk with their hands and slip from English to Italian the way such characters did in Italian-American sitcoms of the last century.

But the music? Removed from that era, Valli’s adenoidal falsetto evokes a giggle, on first hearing. Try to listen to “Sherry,” the group’s screeching first hit, without laughing. But his range was always impressive, as was their longevity — 29 Top 40 hits spanning three decades.

The musical mixes up the songs’ order and exposes their limitations. “My Eyes Adored You,” with the creepy line “though I never laid a hand on you,” gets turned into a lullaby that Frankie sings to his little girl. And becomes even creepier when it does.

The Eastwood film exposes the play’s antecedents. It is structured like “Mamma Mia!” with hints of the group’s most famous and recent hit, “December 1963 (Oh What a Night),” book-ending the plot.

Piazza, as the annoying, overbearing DeVito, is the only member of the group to make an impression. Christopher Walken, playing the benign (of course) mobster who watches over Frankie, is given little to do.

Only Renee Marino, as the Italian spitfire who became Frankie’s first wife, threatens to animate this picture and give it the acting jolt it needs. But doesn’t.

“Jersey Boys” is such a poor reflection of Eastwood’s best work that just when you think, “At least the musician in him does justice to the songs,” there’s a botched horn arrangement in “Can’t Take My Eyes Off of You.”

Just when you think, “Well, there’s a big ensemble dance number coming, and he cast Christopher Walken,” he misses getting the famed dance man in the shot.

So the guy who directed “Bird” has made the worst screen musical since “Rock of Ages.” And it’s little comfort knowing this won’t be his last film, or how he’s remembered. It just makes you fear he’ll end his directing career on an even worse note next year, with “American Sniper.”